DE2614637B2 - Method of manufacturing a coil for a choke coil - Google Patents

Description

20th

The invention relates to a method for producing a coil for a choke coil, in which at least two adjacent, each surrounded by a solid insulating layer and metallic ? ^r > conductors separated from each other are wound together to form a coil and then metallically connected to one another after winding.

Such a process is from Swiss Patent 3,14,113 known J <>

Before such a choke coil can be switched on in an electrical distribution network, the quality of its insulation must be checked with the aid of a test voltage. For soiche examination are known two methods, both of which are complex and require a ^J5 expensive test equipment. According to one method, the coil is supplied with electricity, e.g. B. with the full or with more than the full short-circuit current, so loaded that the required test voltage occurs between adjacent turns of the coil. One must then have a test facility ^ large capacity and performance. In the second case, a capacitor is repeatedly discharged across the coil. A disadvantage of this second method is that the capacitor output must ^{always be adapted to the inductor to be tested 4i.}

The invention is based on the task of checking the winding insulation required before use the aforementioned choke coil wound from several insulated conductors, simple, cheap and with Help to make simple test equipment possible.

This object is inventively achieved in that the coiled conductor are each connected in pairs in front of their metallic bonding at least with its own terminal to a test voltage so ^ss that everywhere the test voltage is substantially same potential difference occurs between adjacent turns of the coil.

The advantages of the method according to the invention are in particular that one for the test the choke coil in this way only needs a simple voltage source that has almost no power to it need to have. By regulating the test voltage, in the event of a short circuit in the network between the Windings of the coil that occur and stress the winding insulation can be easily imitated. It should be noted that with parallel connection of the conductor during operation and with a short circuit only then Induced winding voltage, but when the conductors are connected in series it is a multiple of the winding voltage occurs between adjacent turns of the choke coil Conductors can have different cross-sections, but when they are connected in series, the Cross-sections be the same.

An embodiment of the invention will be explained in more detail with reference to the drawing. In the drawing shows

F i g. 1 is a diagram of a coil wound from two conductors for a choke coil while between them Conductors a voltage difference is generated,

Fig. 2 is an axial section of part of one of two Conductors of the same cross-section wound coil for such a choke coil, during the winding process this coil and

3 shows an axial section of part of one of two Conductors of unequal cross-sections wound coil for one such choke coil.

The coil of FIG. 1 consists of two coiled conductors 1, 2 each, e.g. B. in the way after F i g. 2, are surrounded by a layer of insulating material 3 and form contiguous turns. To the Checking the insulation between the windings is shown in FIG. 1 the conductor 1 with the one terminal a test voltage source 4 and the conductor 2 is connected to the other terminal of this voltage source 4 via earth tied together. Because conductors 1 and 2 are metallically separated from each other during the voltage test are, one of the required test voltage will be the same everywhere between adjacent turns of the coil Voltage difference occur. After the test, the coil is switched off from the test voltage source 4 and the conductors 1, 2 are then metallically connected to one another. The test voltage can be easily the voltage occurring between the windings in the event of a full short circuit is equal to or greater than this Tension to be made.

If the conductors 1 and 2 as shown in Fig.2 have the same cross-sections, they can be connected both in parallel and in series. But if the main conductor 1 is an auxiliary conductor 5, which is used exclusively for testing the insulation, it is essential smaller diameter is added, these conductors can only be connected in parallel in the coil.

The illustrated coils can consist of several concentric cylinders instead of two or several coiled conductors formed cylinder layers, either parallel or can be connected in series.

A great advantage of the method according to the invention is that it requires practically no power and that the insulation can easily be checked so precisely that the level of security is kept low without danger can be, d. H. the insulation layer around the conductor is relatively thin, e.g. B. as a paint layer, can be carried out so that the coils of the choke coil can be made compact and inexpensive can.

1 sheet of drawings

Claims (1)

Claim: Process for the production of a coil for a choke coil, in which at least two adjacent, each surrounded by a solid insulating layer and metallic from each other separate conductors wound together to form a coil and after winding metallic together be connected, characterized by that the wound conductors (1,2; 1,5) before their metallic connection at least in pairs be connected to a test voltage source (4) with its own terminal in such a way that one of the test voltage essentially everywhere between adjacent turns of the coil same potential difference occurs